Field of the Invention
Various embodiments of the present invention relate to the technology to protect a clutch on high-temperature condition of the clutch; and particularly, to a method for protecting a clutch for a dual clutch transmission (DCT) which can protect the clutch without greatly deteriorating drivability of a vehicle when the temperature of the clutch is increased to exceed a specific temperature.
Description of Related Art
Recently, in order to cope with high oil prices and CO2 environmental regulations, improvement of fuel efficiency of a vehicle is greatly required, and thus environmental vehicles, such as electric vehicles or hybrid vehicles, which can improve the fuel efficiency while reducing the discharge amount of exhaust gas have been continuously studied and developed.
Under such current situations, the most realistic countermeasures to improve the fuel efficiency of the vehicle are to improve the efficiency of an internal combustion engine or to heighten power transfer efficiency of a power train system.
On the other hand, a transmission having the most superior efficiency of a driving system is a manual transmission, and a DCT (Double Clutch Transmission) that is based on the manual transmission also has superior power transfer efficiency in comparison to an automatic transmission or a CVT (Continuously Variable Transmission).
The DCT is a system for automatically controlling a manual transmission, and unlike a general automatic transmission that uses a torque converter and a wet type multiplate clutch, the DCT transfers an engine torque using a dry type clutch.
However, the dry type clutch has the drawbacks that it is difficult to cool the clutch when the clutch generates heat and thus the frictional performance of the clutch is considerably lowered to cause the power transfer not to be performed. In this case, clutch slip occurs continuously, and thus clutch fade out occurs to cause trouble of the clutch.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.